Calcium & magnesium supplementation

[Carper]

Hi All,

I use a general feed, Akerne rain mix, of 13.3.15 with calcium @ 11 & magnesium at 4. My simple question is, are the calcium and magnesium levels sufficient or is it possible to add extra that may benefit the plant? If extra can be added, say in the form of calcium nitrate & magnesium sulphate, how much is safe?

I feed at a strength no more than around 500 u/S using RO water. I just add the feed until the correct strength is achieved. I adjust the ph normally down from around 6.4 to 5.9.

I normally mix up my main feed to around 300 u/S then around once a month add about 100 u/S of Epsom salts for the magnesium. This does seem to benefit the plants so my thoughts are now turning to added calcium but at safe levels along with the magnesium.

Thanks all

Gary
UK

 

[Ray]

Hi, Gary.

I think you're OK, as-is.

Have you experienced any cases of new growth tips turning black? If so, that is an indication of insufficient calcium.

 

[Carper]

There are a few of these where roots seem to start with good growth then the root tips do turn brown/black and stop! A few of my plants have quite pale yellow leaves which seem to be getting worse. They curl a little around the edges and feel quite thin as though they require something extra! There are no signs of disease etc

Gary

 

[consettbay2003]

There are a few of these where roots seem to start with good growth then the root tips do turn brown/black and stop! A few of my plants have quite pale yellow leaves which seem to be getting worse. They curl a little around the edges and feel quite thin as though they require something extra! There are no signs of disease etc

Gary

Ammonium sulphate

 

[gonewild]

There are a few of these where roots seem to start with good growth then the root tips do turn brown/black and stop! A few of my plants have quite pale yellow leaves which seem to be getting worse. They curl a little around the edges and feel quite thin as though they require something extra! There are no signs of disease etc

Gary

The symptoms you describe fit with ammonium toxicity.
Does the fertilizer contain ammonium nitrogen?

 

[Luca69]

The symptoms you describe fit with ammonium toxicity.

Does the fertilizer contain ammonium nitrogen?

No, N on Akerne Rain mix is essentially nitrate. It has less than 1% of ammonium.


Luca

 

[Carper]

The symptoms you describe fit with ammonium toxicity.
Does the fertilizer contain ammonium nitrogen?

No Lance, there is no urea nitrogen source within the feed.

Gary

http://www.akerne-orchids.com/shop/index.php?route=product/category&path=40

 

[gonewild]

What plants are doing poorly? Paphs?

You are adding extra Magnesium but not extra Calcium, correct?

Do you know the pH of your media?

 

[Stone]

Hi All,

I use a general feed, Akerne rain mix, of 13.3.15 with calcium @ 11 & magnesium at 4. My simple question is, are the calcium and magnesium levels sufficient or is it possible to add extra that may benefit the plant? If extra can be added, say in the form of calcium nitrate & magnesium sulphate, how much is safe?

I feed at a strength no more than around 500 u/S using RO water. I just add the feed until the correct strength is achieved. I adjust the ph normally down from around 6.4 to 5.9.

I normally mix up my main feed to around 300 u/S then around once a month add about 100 u/S of Epsom salts for the magnesium. This does seem to benefit the plants so my thoughts are now turning to added calcium but at safe levels along with the magnesium.

Thanks all

Gary
UK

Gary, With your N at 13% and your Ca at 11% you are giving too much Ca already in my opinion - or not enough N. What are the boron levels? The plant just does not need that much Ca. It needs N to make cells so if that is restricted it makes no sense to give it extra Ca which it simply cannot use fast enough. I'm pretty sure that Ca is taken up passively so you really are not going to see deficiencies unless the mix is highly acidic, you are using pure water and you're not adding any to the feed. Very rare that happens.
I noticed that browned off root tips lessened when I increased the N...but not as Calcium nitrate. I use dolomite for most of the Ca and Mg.

 

[abax]

If you can acquire Orchiata and K-Lite in the UK, that should solve any problems with Ca/Mg. I find the two
used together provide excellent nutrition for my Paphs.

 

[gego]

With paphs, I have the same problem when using bark and nitrates. Easy on K with bark, it has enough to supply your plant.

 

[Carper]

What plants are doing poorly? Paphs?

You are adding extra Magnesium but not extra Calcium, correct?

Do you know the pH of your media?

Lance,

I have tested the PH of the media by passing through RO water in a few of the pots and it is coming out around the 6 - 6.2 range.

Gary

 

[Carper]

Gary, With your N at 13% and your Ca at 11% you are giving too much Ca already in my opinion - or not enough N. What are the boron levels? The plant just does not need that much Ca. It needs N to make cells so if that is restricted it makes no sense to give it extra Ca which it simply cannot use fast enough. I'm pretty sure that Ca is taken up passively so you really are not going to see deficiencies unless the mix is highly acidic, you are using pure water and you're not adding any to the feed. Very rare that happens.
I noticed that browned off root tips lessened when I increased the N...but not as Calcium nitrate. I use dolomite for most of the Ca and Mg.

Mike,

The recommended strength for the feed is around 650/700 u/S. I used to feed at these levels but found that the plants seemed to growing just as well at the lower levels. I do lower to around 250/300 u/S through winter due to the british climate. An option may be to increase the feed strength to possibly the recommended levels to increase the N especially as we are approaching spring/summer.

Gary

 

[Carper]

If you can acquire Orchiata and K-Lite in the UK, that should solve any problems with Ca/Mg. I find the two
used together provide excellent nutrition for my Paphs.

All my plants are in orchiata and I have found it to be the best media for my growing. I have used K-lite and as stated in previous threads I had some poor reactions from plants, ie yellowing of leaves etc so will no longer use it as my plants have now mainly recovered. I may experiment with it again on a few plants in the future but it is not part of my main feeding programme at the moment.

Gary

 

[gonewild]

Mike,

The recommended strength for the feed is around 650/700 u/S. I used to feed at these levels but found that the plants seemed to growing just as well at the lower levels. I do lower to around 250/300 u/S through winter due to the british climate. An option may be to increase the feed strength to possibly the recommended levels to increase the N especially as we are approaching spring/summer.

Gary

Were the plants that are doing poorly now growing well before you decreased the strength? You can probably see where I am headed with that question.

The basic MSU formula provides enough calcium assuming the pH is correct so as Ray says a calcium deficiency is not likely. Your pH is not low so that also points away from calcium being the problem.

You said you are adjusting the pH of the fertilizer solution down, what are you using to do that?

The reality is that the MSU studies resulted in a recipe that gave great results. BUT the recipe calls for feeding at a certain strength of nutrients. They came up with that based on the combined ratios of nutrients. Your first move should be to increase the Akrane back to the recommended rate and see if the plants improve.

Dont assume that because people are having good results with using K-lite at very low nutrient levels that you will also get good results at low levels of Akrane.

Consider also that the few symptomatic plants may have a disease or nematode infestation.

 

[Ray]

The reality is that the MSU studies resulted in a recipe that gave great results. BUT the recipe calls for feeding at a certain strength of nutrients. They came up with that based on the combined ratios of nutrients.

Sorry, Lance, but in direct discussions with the developer, I have been told that there was absolutely no scientific basis to their decision to test at 125 ppm N. Quoting directly, "We tried that, and it worked.", but that was at a weekly application rate.

 

[Carper]

Were the plants that are doing poorly now growing well before you decreased the strength? You can probably see where I am headed with that question.

The basic MSU formula provides enough calcium assuming the pH is correct so as Ray says a calcium deficiency is not likely. Your pH is not low so that also points away from calcium being the problem.

You said you are adjusting the pH of the fertilizer solution down, what are you using to do that?

The reality is that the MSU studies resulted in a recipe that gave great results. BUT the recipe calls for feeding at a certain strength of nutrients. They came up with that based on the combined ratios of nutrients. Your first move should be to increase the Akrane back to the recommended rate and see if the plants improve.

Dont assume that because people are having good results with using K-lite at very low nutrient levels that you will also get good results at low levels of Akrane.

Consider also that the few symptomatic plants may have a disease or nematode infestation.

I have been feeding at these lower levels for a couple of years now and looking back, most of the plants seem very healthy. Most are multifloral paphs and species but they do seem to have taken a good couple of years to get to their present stage, when they were nr FS then. We certainly don't get the culture, ie light levels & heat etc in the UK that most others get so I have tried to take precautions in the strength of the feed I give. I will increase the feed to recommended levels & monitor. I use Dyna Gro bloom to lower the PH, which as the Akerne comes out at around 6.2, only takes a few drops, but then to up the PH, I use Dyna Gro Pro-Tekt. When I feed the bloom, which drops the ph to around 4.5 I use the Pro-tekt to bring it back up to around 5.9.

Gary

 

[myxodex]

The problem might not have anything to do with your feeding regime. I would check very carefully for pests and make sure that this issue can be excluded before worrying about nutrient supply.

I grow indoors in the UK and I've had a problem from small slugs living in the medium and eating the root tips. I've seen them in action with a hand lens. Both my paphs and my neos have been affected at different times by these ... and they're small (<= 1 cm), dull gray-brown and so not easy to see. Over the years I've learned that they can come in with new plants. They do not take slug bait and I suspect that they might be a bit of a problem in some EU nurseries.

I've also had thrips and millipedes in my potting medium coincidental with a root termination problem and I suspect these may also cause this problem. The root tips are very vulnerable. It just takes a small amount of damage, maybe even an exploratory nibble from something like a millipede perhaps, to cause infection and terminate a root tip. I wish there was a safe drench to eliminate all medium pests ... if anyone knows ?

From what I've read, calcium is mainly taken up via the root tip and if the root tips are being taken out then a secondary problem could be a calcium limitation (probably other nutrients also) ... but increasing calcium in your feed is not going to help if the primary problem is from pests.

 

[Carper]

The problem might not have anything to do with your feeding regime. I would check very carefully for pests and make sure that this issue can be excluded before worrying about nutrient supply.

I grow indoors in the UK and I've had a problem from small slugs living in the medium and eating the root tips. I've seen them in action with a hand lens. Both my paphs and my neos have been affected at different times by these ... and they're small (<= 1 cm), dull gray-brown and so not easy to see. Over the years I've learned that they can come in with new plants. They do not take slug bait and I suspect that they might be a bit of a problem in some EU nurseries.

I've also had thrips and millipedes in my potting medium coincidental with a root termination problem and I suspect these may also cause this problem. The root tips are very vulnerable. It just takes a small amount of damage, maybe even an exploratory nibble from something like a millipede perhaps, to cause infection and terminate a root tip. I wish there was a safe drench to eliminate all medium pests ... if anyone knows ?

From what I've read, calcium is mainly taken up via the root tip and if the root tips are being taken out then a secondary problem could be a calcium limitation (probably other nutrients also) ... but increasing calcium in your feed is not going to help if the primary problem is from pests.

I always strip down the plant and put in fresh medium whenever I purchase any new plant. I check very carefully for pests or any diseases and treat accordingly. Checking my plants on a daily basis, especially as I mainly use clear pots is quite routine and I've not come across any slugs for quite a while. I do think this is down to feeding culture, but it is always good to eliminate all possibilities.

Gary

 

[gonewild]

Sorry, Lance, but in direct discussions with the developer, I have been told that there was absolutely no scientific basis to their decision to test at 125 ppm N. Quoting directly, "We tried that, and it worked.", but that was at a weekly application rate.

Ray, I don't know why you are sorry?
Many years before MSU published their results scientific trials were done that established the strength liquid fertilizer should be. The work was done at Purdue and UC Davis by a very good friend of mine. When I first saw the MSU formula it appeared to be an exact copy of the nutrients we had been using for years. The rate of 125ppm N is of course approximate but the overall strength of the total solution is the same. And the 125ppm N will give a total of about 600ppm. That rate was found to be very good as constant feed in greenhouse production, actually on the low side. Now if you say the "developer" says they took a wild guess at the rate then maybe they simply used knowledge that was already known, ran some trials and published the results.